ngs and deck
fittings--such as bilge pumps, companionways, skylights, binnacles,
wheels and wheel-rope trunks, cable trunks, steampipe casings, and stack
fiddleys--have been located in an effort to meet the imagined
requirements of the working of a ship of this unusual form.

[Illustration: Figure 19.--MODEL OF _Steam Battery_ in the Museum of
History and Technology. (Smithsonian photo 63990-E.)]

[Illustration: Figure 20.--LINES OF STEAMER _Congo_, built in 1815-1816
for the British Admiralty and converted to a sailing survey vessel. From
Admiralty Collection of Draughts, National Maritime Museum, Greenwich.]

There are some unanswered questions that arose in the preparation of
the reconstruction drawings. As has been shown, the original inboard
arrangement plan found in Copenhagen shows four smokestacks, while
Marestier's sketch of the vessel's boilers shows trunked flues
indicating that two stacks were used. It is possible that the boilers
were first fitted so that four stacks were required; alterations made as
a result of steaming trials may well have included the introduction of
trunked flues and the final use of two stacks in line fore-and-aft. This
would have required a rearrangement of the fiddley hatches amidships.

Another troublesome question was the doubtful arrangement of the four
companionways on the spar deck. Perhaps only two were fitted, one on
each side of the officers' staterooms while the ladderways at the crew's
end of the ship were simple ladder hatches.

The decision to use four bilge pumps is based upon the lack of drag in
the keel of the hulls, which would prevent accumulation of bilge water
at one end of the hull. The use of four single-barrel pumps instead of
four double-barrel pumps may be questioned, for chain pumps requiring
two barrels would have been practical.

Allowance for stores was made by use of platforms in the hold. It is
known from statements made to the Court of Inquiry, that the magazines
were amidships and that a part of these was close to the boilers. Fuel
and water would be in the lower hold under the platforms; hatches and
ladderways are arranged to permit fueling the ship.

A few prints or drawings of the ship, aside from the patent drawing,
have been found. There are two prints that show the launch of the
vessel. One, a print of 1815, is in possession of the Mariners' Museum,
Newport News, Va., and is reproduced in Alexander Crosby Brown's _Twin
Ships, Notes on the